Type head tilt and rotating mechanism

ABSTRACT

A tilt bridge for a type carrier carries unitarily rotatable thereon a type carrier and a gear, and such gear is in constant engagement with another gear at an axis location whereabout the tilt bridge is required to tilt. The gear on the tilt bridge has freedom for tilting movement about said axis location in respect to the other gear and is in constant mesh therewith for receiving therefrom rotary type-selective movements for the type carrier. The tilt and rotate axes are mounted on a swingable support whereby the carrier may be swung to print.

United States Patent 1191 Decker July 23, 1974 [5 TYPE HEAD TILT ANDROTATING 3,674,126 7/1972 Decker et al. 197/55 MECHANISM 3,703,23011/1972 Glave 197/52 [75] Inventor: Herbert Decker, Lauf, Germany OTHERPUBLICATIONS 73 A 1 T h w k N b H. E. Merritt, Gears, Sir Isaac Ritman &Sons Ltd., Sslgnee N l l r l ergfefma h y erg (3rd ed.), 1954, pp. 8-9and 372-375.

[22] Filed: 1972 Primary Examiner-Robert E. Pulfrey 21 APPL 30 22Assistant Examiner-R. T. Rader Related US. Application Data [57] IABSTRACT 63 1 58:52:25? of Ser No 1970 A tilt brldge for a type earnercarries unitarlly rotatable thereon a type carrier and a gear, and suchgear 52] us. c1. 197/55, 197/18 is in constant engagement with anothergear at an axis 51 1111. c1 B41] 1/32 locatiohwhereahout the tih bridgeis required to 58 Field of Search 197/16, 52, 19, 55, 18; The gear onthe tih bridge has freedom for hing 178/34 movement about said axislocation in respect to the other gear and is in constant mesh therewithfor re- [56] References Cited ceiving therefrom rotary type-selectivemovements for UNITED STATES PATENTS the type carrier. The tilt androtate axes are mounted 2 895 584 7/ Son at a 197/52 on a swingablesupport whereby the carrier may be 219051302 9/1959 l-lickerson swung topunt 3,286,806 11/1966 Schoenfelder 197/16 7 Claims, 3 Drawing FiguresPAlimmJmzamu V 5, 35,102

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ATTOR NEY , 1. 1 TYPE HEAD TILTAND ROTATING MECHANISM This is acontinuation of copending US. application Ser. No. 76,733, filed Sept.30, 1970, now abandoned.

BACKGROUND OF THE INVENTION In connection with type carriers, intypewriters and similar machines which bear a plurality of typecharacters in vertical columns and horizontal rows, this inventionconcerns a provision for selectively positioning such type carrier foreffecting type selections.

The positioning of such carriers for any givencharacter selectionrequires a turning and tilting motion of the type carrier. In order toprovide for both such motions, a motion transmitting joint becomesnecessary which connects the type carrier and the motion axis in ahingedly jointed manner for smooth motion transmittal. The type carriercan be generally sphere-shaped like with a joint in its center thereof,or it can be barrel shaped. In the latter case a joint is required whichaffordsa center of a radius curvature in accord with which said barrel'is shaped. For type carriers which are strictly of cylindrical form andhave several rows of characters located in different horizontal rowsmerely axial motion of the type carrier is required.

A. U.S. Pat. No. 2,895,584 issued July 1, 1959 to .I. E. Hickerson etal. (German Pat. No. 1,063,612), shows that it is well known to positiona sphere shaped type carrier by use of two crown gears which haveintermediate thereof another crown gear, the axis of such latter crowngear being coincident with the tilting axis of the carrier in order toachieve constant control over the type carrier by said gears. Becausethe sphere shaped type carrier is small, its hollow interior in whichthe joints for the gears have to be accommodated are of necessity verysmall, so that very fine manufacturing tolerances are necessary whichraise the cost of manufacture. Furthermore, there is greatlyaccumulating play in the motion train between the rotating axis and thetype carrier, and such play includes the working clearance betweenthethree crown gears and the pivots therefor. Consequently, in order tohold the total play within acceptable limits, very special and expensiveaccuracy in all the pertinent parts is required.

In another known execution shown in said I-Iickerson .et al. patent (DPS1,063,612) of a positioning mechanism for a sphere shaped type carrier adouble cross or "universal joint is used to connect the rotating axisand the rotating type carrier. Although this cross joint was simplifiedas compared to the usual cross joints, it has similar disadvantages asdescribed above with the crown gears arrangement which take the functionof a joint. Here too play enters into it twice at the two grooves of thejoint members and at the pins of the ro-.

tating axis and on the rotating member onto which the type carrier ismounted- One such connecting member which .is located within the sphereshaped type carrier allows only relatively small links to transmit theforces from the rotating axis to the type carrier. The links are inaddition shortened when the carrier is moved into its furtherestpositions. A further disadvantage is that because of the amount ofrotation which is necessary a certain distance of the joints from thecenter is required, taking up so 'much space of the space availableinside the type carrierthat there is very little'space left to mount therotating member which carries the type 2 carrier in the axialdirection.Therefore themounting was put on the outside of the joint causing themounting to have a large diameter which increases the friction.

' Another joint connection became known for a barrel shaped typecarrier, see US. Pat. No. 3,286,806 issued to H. Schoenfelder on Nov.22,- 1966 (French Pat. No. 1,411,426), which consists of a sleeve on therotating axis and a pin in the rotating member which carries the typecarrier. Although with such a joint, it is possible to turn the typecarrier and at the same time to tilt it to select a row, a varyingmotion results from such structure, as is well known. This means thatspecific different angular rotations of the driver shaft produce at thetype carrier angular motions which are differing therefrom. Thiscondition for positioning the type carrier is unacceptable inasmuchasfor detenting purposes these differing angular motions have to becorrected before printing. For machines with a constantly rotating typecarrier it would require supplemental timing corrections. From this itfollows that with type carriers which are turned and tilted toselectively position a particular character, a homokinetic joint isrequired.

SUMMARY or THE INVENTION Underlying the invention is an object toprovide for a rotatable and tiltable type carrier, a joint which willnot produce discrepancies of angular motion transmittal between a primerotating shaft for-such carrier and the carrier in any rotating ortilting range of the type carrier. Furthermore, the requirement is thatthe connecting joint is within the type carrier and is of simplestructure and such as to hold loose play in the drive to the typecarrier to a minimum. 7

These objects of the invention are attained in that a connecting jointor provision consists of two gears, which locally mesh and of which onegear is swingable about the location where they locally mesh. Theconnecting joint is within the barrel-shaped type carrier, and comprisestwo gears which locally are always in full meshing association where thetilt axis for the type carrier is situated.

DESCRIPTION OF DRAWINGS DESCRIPTION OF PREFERRED EMBODIMENT On a guiderail 1 which is carried between sidewalls of the machine frame, notshown, there is a guided swingably a type carrier support 2. A lowertransverse web 3 and an upper transverse web 4, both being a part of thesupport 2, have respectively holes 5 and 6 which give rotating supportto a shaft 7. The lower end of the shaft 7 carries a guide disk or drum8 whereby it is rotatable. Above the web 4 the shaft 7 carries a crowngear which by a shoulder 9 thereof rests on said web 4. Furthermore, thetype carrier support 2 has integral, laterally spaced upwardly extendingbearing arms 11 and 12, having each a hole 13 at the upper end thereofwhereinto axle studs l4carried on a tilt member or bridge 15 extendthereby to mount such tilt bridge 15 tiltably on the support 2 on a tiltaxis which is defined by said holes 13 and the studs 14. A gear 16 inthe form of a crown gear is carried fast on an axle 18 by a nut 17. Theaxle 18 is rotatively supported in a bearing 20' on the tilt bridge 15with a shoulder 19 rests on the axle 18 resting on the bearing 20. Thetilt bridge 15 includes a lever arm 21 depending therefrom and having ahole 22. The upward extending end 23 of the axle 18 is threaded andserves to fasten a barrel-shaped type carrier 24 upon the axle 18between shoulder 19 and a shoulder of a serrated nut 25 when the nut 25is applied thereon. The type carrier 24 has type characters 26 arrangedthereon in well known manner, in vertical columns and horizontal rowsand so that the type characters 26 can be brought selectively intoprinting position at the platen 27. I

In order to bring a given type character 26 on the type carrier 24. intoa position for printing against the platen 27 at a printing point, it isrequired to impart a rotating motion and tilting'motion tothe typecarrier 24, and further to swing the type carrier 24 by the support 2toward the platen 27 about the guide rail 1. The rotating motion istransmitted to the type carrier 24 by a drawband, not shown, which actsturnably on the drum 8 to turn the shaft 7 and the crown gear 10thereon. The crown gear 16 which is mounted on the tilt bridge 15 is inconstant engagement with the lower crown gear 10 at a location where thepitch circles of the crown gears 10 and 16 locally meet and at whichlocation furthermorethe tilt axis defined by the holes 13 and the studs14 is tangent with the pitch circles of crown gears 10 and 16. Becauseof this geometric arrangement it is possible to rotate the type carrier24 selectively while at the same time a tilt motion is imparted to thetilt bridge'15 via the arm 21, by a drive, not shown. To effect animprint, the support 2 for the type carrier 24 is mounted on the guiderail 1 for swinging movement against the platen 27, the support 2 havingnormally a position wherein the type carrier 24 stands swung away fromthe platen 27. Drives for effecting swinging movements of the typecarrier 24 are known to exist in different forms and it is not thoughtnecessary to give an explanation thereof.

The device of the invention facilitates the positioning of a typecarrier 24 of generally spheric or barrel-- shaped, rotatable form, sothat regardless of the tilt position which may be given to the tiltbridge 15, the type carrier 24 will always receive from the shaft 7 therequired rotative positioning movement via the gears 10, 16. For thetransmittal of the homokinetic motion there are required only two partsnamely the two gears 10, 16 which preferably may be generally of thecrown gear species shown. Therefore, there is no chance for accumulativeplay, such as is prevalent when universal joint mechanisms are used. Afurther advantage of the invention resides in the fact that the twogears 10 and 16 of large diameter can be accommodated within the typecarrier 24 yet require very little space in the axial direction, as canbe observed especially in FIG. 2. It is for this reason that themounting means of the rotating shaft 7, as well as the type carrier 24,can be of such efficiently.

. 4 structure thatthe parts will operate not only functionally withprecision but are also produceable simply and The connecting joint ofthe invention, compared to joints involving apin and a slidable fit witha bushing,

has alsospecial advantages afforded by the fact that there is a virtualabsence of friction. Thus, wear is reduced so that better accuracy ofoperation prevails. Furthermore, the forces for transmittal of rotatingmotion are active far from the rotation axes of the shafts 7 and 18 andthe contact pressure is thus most favorable and uniformly active in anyof the various tilt positions of the type'carrier 24.

It is, of course, not necessary that the gears 10 and 16 be'of equaldiameter so that their pitch circles, which obviously are both tangentto the tilt axis, can correlatedly be of differing diameter.

' The invention claimed is: I

l.'In combination with a single element type carrier having a hollowinterior and having type characters located in columns and rows on itsexterior surface, said carrier being mounted to be selectively tiltablyand rotatably positioned to present selected type characters thereon forprinting ata printing point, tilt and rotate positioning structureadapted to be received within said hollow interior of said type carrierand to mount said port means,

a drive gear and associated axle rotatably mounted on said supportmeans, I

a tilt member pivotally mounted on said support means, v

and a driven gear and associated axle rotatably mounted on said tiltmember,

said type carrier being mounted on said driyen gear axle after receivingsaid tilt and rotatestructure within its hollow interior, a

said mounting of said gears and tilt member on said support means beingarranged to maintain said gears in constant mesh with their pitchcircles tangent to the pivot axis of said tilt member.

2. In a machine having a single element type carrier characterized by ahollow interior and type characters arranged in rows and columns on itsexterior surface, and mechanisms receivable within said hollow interiorfor mounting and for transmittingrotational and tilting motions to saidsingle element type carrier to present a type character on a selectedrow and column for printing at a printing point comprising,

a support member having an end located within the hollow interior ofsaid type carrier,

a tilt bridge pivotally mounted on the end of said support member withinthe hollow interior of said type carrier and tiltable about its pivotaxis to present a selected row of type characters for printing at saidprinting point,

a rotate shaft rotatably supported in said tilt bridge type carrier,said positioning structure comprising supand coaxially supporting saidtype carrier thereon,

second gears tangent to the pivot axis of said tilt bridge. 3. Theinvention defined in claim 2, said first and second gears being crowngears.

4. The invention defined in claim 2, said single element type carrierbeing barrel shaped.

5. The invention recited in claim 2,

said printing point being defined by a stationary platen,

said support member being pivotal about an axis external to said typecarrier to swing said single elewhere the axis of said rotate shaft isvertically oriented. l

UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTION QPATENT NO. 3,825,102

DATED 1 July 23, 1974 INV ENTOR(S) 1 Herbert Decker It is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In The Heading:

After item [21], insert --Foreign Application Priority Data December 18,1969 Germany. .l9634776-- Signed and Scaled this Sixteenth D y fNovember 1976 [SEAL] Attest:

RUTH C. MASON C. MARSHALL DANN Arlestmg' Office Commissioner oj'PalenIsand Trademarks

1. In combination with a single element type carrier having a hollowinterior and having type characters located in columns and rows on itsexterior surface, said carrier being mounted to be selectively tiltablyand rotatably positioned to present selected type characters thereon forprinting at a printing point, tilt and rotate positioning structureadapted to be received within said hollow interior of said type carrierand to mount said type carrier, said positioning structure comprisingsupport means, a drive gear and associated axle rotatably mounted onsaid support means, a tilt member pivotally mounted on said supportmeans, and a driven gear and associated axle rotatably mounted on saidtilt member, said type carrier being mounted on said driven gear axleafter receiving said tilt and rotate structure within its hollowinterior, said mounting of said gears and tilt member on said supportmeans being arranged to maintain said gears in constant mesh with theirpitch circles tangent to the pivot axis of said tilt member.
 2. In amachine having a single element type carrier characterized by a hollowinterior and type characters arranged in rows and columns on itsexterior surface, and mechanisms receivable within said hollow interiorfor mounting and for transmitting rotational and tilting motions to saidsingle element type carrier to present a type character on a selectedrow and column for printing at a printing point comprising, a supportmember having an end located within the hollow interior of said typecarrier, a tilt bridge pivotally mounted on the end of said supportmember within the hollow interior of said type carrier and tiltableabout its pivot axis to present a selected row of type characters forprinting at said printing point, a rotate shaft rotatably supported insaid tilt bridge and coaxially supporting said type carrier thereon, afirst gear coaxially secured to said rotate shaft within the interior ofsaid type carrier, and means to transmit rotational movement to saidtype carrier to present a selected column of type characters forprinting at said printing point including a second gear rotatablysupported on said support member within said hollow interior of saidtype carrier and located to be in constant mesh with said first gear andwith the pitch circles of said first and second gears tangent to thepivot axis of said tilt bridge.
 3. The invention defined in claim 2,said first and second gears being crown gears.
 4. The invention definedin claim 2, said single element type carrier being barrel shaped.
 5. Theinvention recited in claim 2, said printing point being defined by astationary platen, said support member being pivotal about an axisexternal to said type carrier to swing said single element type carrierfrom a rest position toward said platen to print.
 6. The inventionrecited in claim 5, said pivot axis of said tilt bridge being locatedopposite said platen from said rotate shaft and being located on a lineextending through the printing point on the platen.
 7. The inventiondefined in claim 3, the axis of rotation of said second gear having atleast a predetermined inclination with respect to the axis of saidrotate shaft when the type carrier has been tilted to a position wherethe axis of said rotate shaft is vertically oriented.